Often, many modem, large scale manufacturing projects require the interconnection of many different components and subassemblies. However, in order to fully take advantage of mass assembly, the manufacture, routing, and testing of such interconnections demands standardized routing, facile testing capabilities, and quick and accurate information pertaining to the interconnections. Such interconnections may range from standard electrical wire connections to fiber optic connections. However, regardless of the physical characteristics of the medium, the above requirements remain. Thus, the present invention provides a software system which aids in the manufacture, design, and testing of wiring harnesses, by first acquiring the requisite data from a Computer Aided Design/Computer Aided manufacturing (CAD/CAM) system, and by further displaying the referenced information graphically in a form that facilitates these activities.
An electrical wiring harness typically comprises a bundle of individual wires of varying gauges, impedances, and types, all arranged in a particular order. These wiring harnesses are typically bound together in order to facilitate the installation, repair and maintenance of the wires, and the connection of multiple remote systems. Such wiring harnesses are used in a variety of industries. In the aircraft industry, for example, wiring harnesses are used to interconnect the various electrical components and subassemblies of the multitude of systems located within an aircraft. However, they may also be used in virtually any industry where there is a need to interconnect a plurality of electrical components. For example, the automobile industry also uses such wiring harnesses.
A typical wire harness utilized in aircraft manufacture has an average of eight connectors per harness. Further, each wiring harness typically has at least one segment end containing wires to which electrical splices have been made or to which lug-type contacts have been applied. Typically, an average of five different wires types and gauges are used in a harness. Moreover, an average of one hundred wires per harness and twenty-eight wires per segment end are commonplace. Additionally, the harness may contain twisted pairs of wires, which in turn may have very large gauges, ranging from 0.047 inch to 0.084 inch.
In order to manufacture a typical wiring harness as detailed above, a large percentage of the work is accomplished manually. An individual wire is first coded with an identifying mark, and then cut to a predetermined length. Subsequently, the segments which will form a single wire harness are sent to a fabricating station where they are manually laid down on formboards. A formboard is typically a large, rigid framed area, usually made of plywood. The wire harness to be manufactured is then laid out and arranged on the formboard. Forming pegs are inserted into holes drilled in the formboard at appropriate locations to facilitate the routing of wires of any individual segment. In order to route wires on a formboard the connector from a first segment is placed at the appropriate location on the formboard. To accomplish this, a technician typically first searches for a prepared wire from a pile of wires, and then searches for a wire number in a data sheet. The wire number corresponds to the identifying mark that was imprinted on the wire while it was being prepared. The data sheet is commonly referred to as a "shop aid". Since a wire bundle can contain thousands of individual wires, the shop aid may consist of a multitude of pages corresponding to the various pieces of data associated with each of the individual wires. Merely locating the entry for a wire in the shop aid is time consuming and thus costly. Additionally, each time that the shop aid and wire harness maps are referenced, a potential for error is introduced. For example, a wire characteristic may be incorrectly read from the shop aid. Similarly, an incorrect wire location may be read from the wire map. This may occur often, since the shop aids are typically large books written in small font type. Accordingly, when a technician looks up a wire code in the shop aid, it is possible that incorrect data will be recorded. Moreover, once the wire number is found in the shop aid, the data provided typically only includes end equipment information (usually connectors and pin numbers) for the wire route. Therefore, the technician must still locate the equipment to be connected on a full scale wiring drawing and determine the path of each individual wire that is to be routed.
After the wire harness has been constructed on the formboard, it is then typically transferred to another fabrication station. At this station, the segments are stripped and the pin-type contacts are applied. Thereafter, the pin-type contacts in each segment must again be inserted into appropriate sockets in a multiple plug-type connector. To accomplish this, another technician must again locate the individual wire in a segment end, and identify it by the identifying mark imprinted on the wire. Again, the technician must then look up this code in the shop aid, and insert the appropriate pin-type contact on the individual wire into the appropriate socket in the connector. Once again, referencing the cumbersome shop aid is a tedious, error prone, and time consuming task.
Subsequently, the harness is installed on a subassembly and placed on a testing machine where the harness is tested for correct wire placement, continuity, and other various electrical tests. If a wire harness fails a specific test, the harness must be repaired. Once again, depending on what type of error is encountered, this process may well include referencing the shop aid for specific wire characteristics.
Similar problems are encountered when maintaining a wire harness after it has been installed. For example, in an aircraft, a technician servicing a wire harness will need to know the various characteristics of the individual wires, where they are connected, etc. This will again entail referencing the shop aid. Moreover, in this situation, the technician will most likely be working in an enclosed, cramped area, where use of the bulky shop aid is not at all practical.
Another disadvantage encountered when using the shop aid occurs when the wiring harness, or individual wiring data within the wire harness must be updated or revised. Under the above described scheme, a significant amount of time and effort is expended in updating, re-planning, and redistributing revised shop aid packages.